This invention relates to roll up doors for use with cargo storage spaces such as on truck bodies.
Roll up doors are commonly used on trucks or trailers, but also are used in garages and the like. In FIG. 1, truck 10 has a body 12 and a conventional roll up door 14. The body typically forms a cargo storage compartment and may be on trailer. The roll up door may be used with other than truck storage bodies, such as cargo containers or buildings, for example. The roll up door 14, FIG. 2, comprises a plurality of rectangular panels 16 which may be wood, metal or other materials or combinations thereof As shown if FIG. 5, the panels 16 may have mating adjacent tongue and grooves 18 in region 4.
The panels 16 are interconnected by hinges 20. The hinges 20 are attached to the panels 20 with fasteners (not shown). These fasteners may protrude through the panel to the opposite side and may be unsightly. The door 14 has a lower sill 22 to which a handle and latch 24 are attached for latching the door to a mating latch 26 on the body 12, FIG. 1.
A conventional spring mechanism 28 preloads the door 14 to permit it to be manually raised and lowered. A pair of opposite mirror image tracks 30 receive rollers 32 and 34 attached to the panels 16 at opposite panel ends. In FIG. 3, a bracket bearing assembly 36 is bolted by bolts 38 which pass through the panels 16. These bolts are visible externally and are also unsightly. Bearing 40 receives axle 42 attached to roller 32. The roller 32 rides within track channel 44 of track 30. A similar bearing assembly is attached to the lowermost panel of panels 16 and at the opposite ends of the uppermost and lowermost panels 16. The axles rotate in the mating bearing journals.
Combined hinge and bearing assembly 46, FIG. 4, is attached between and to each pair of adjacent panels 16. In FIG. 4, the assembly 46 comprises a bracket and hinge 48 which is bolted to and between adjacent panels 16 at each end of the panels. A bearing bracket 50 is attached to the hinge 48. The hinge 48 and bracket 50 form a bearing journal for axle 52 attached to roller 34. A hinge 48, bracket 50, mating axle 52 and roller 34 are secured to each pair of adjacent panels 16 at opposite ends of the panels. The axles 42 and 52 axially slide in the mating bearings and are captured with the attached rollers by the tracks 30 and panels.
The door 14 rolls up and down the tracks 30 via the rollers captured to the tracks. The bolts securing the bearing assemblies 36 and 46 pass through the panels 16, are unsightly and also make it difficult to attach decals, silk screening decorations and indicia and the like on the door external surface. Such doors also use numerous components such as brackets, screws and bolts which add cost to the door.
The present invention is a recognition of this problem and provides a solution thereto, as well as provides a less costly door with less parts than the prior art door described above.
A roll up door for a space having a door opening and for use with spaced roller tracks adjacent to the opening according to the present invention comprises a one piece flexible sheet member dimensioned to enclose the opening and a plurality of stiffening panels secured to the flexible sheet member in a spaced array and arranged to receive rollers for engagement with the tracks whereby the flexible sheet member forms a living hinge in the space between adjacent pairs of the stiffening panels.
In one aspect, the stiffening panels have opposing first and second ends, a plurality of bores in each end, a like plurality of axles each with a wheel secured thereto for rolling in the track, an axle being receive in each bore.
In a further aspect, the stiffening panels are secured to the flexible sheet member by bonding with an adherent material.
In a further aspect, the stiffening panels and the flexible sheet member comprise plastic material.
Preferably the stiffening panels comprise a composite plastic material and have a thickness in the range of about 0.75 to about 1.0 inches. More preferably, the flexible sheet member comprises a composite plastic material having a thickness in the range of about 0.03 to inches to about 0.10 inches.
In a further aspect, the flexible sheet member comprises a sheet material with opposing planar faces. In a still further aspect, the stiffening panels each comprise a flat sheet material portion and first and second edge portions, the edge portions being semi-cylindrical in transverse shape.
Preferably the stiffening panels have a given thickness, the edge portions being defined by a diametrical dimension, the diametrical dimension being greater than the given thickness.
In a further aspect, the spacing of adjacent pairs of stiffening panels is sufficient for the flexible sheet member to bend in a direction which displaces the stiffening panels of an adjacent pair toward each other.
In a still further aspect, a roll up door according to the present invention comprises a one piece flexible sheet member for forming a doorway enclosure; a plurality of stiffening panels with opposing ends; and means for securing the panels to the sheet member in parallel spaced relation to each other and arranged to receive axles of rollers at opposing panel ends whereby the sheet member forms a living hinge in the region between adjacent panels.